It is suggested that you get 1/2 a size or 1 size bigger then what you normally wear. I did that the 1/2 size part and it fit me perfectly. Im a size 8.5 on Timberland and size 8 on Sketchers but Im a size 9 on the XCR. It feels comfortable as well and I use it daily in NYC. Its been snowing but still has plenty of grip. Since it was stated waterproof, I decided to play around and put the mesh part ( the area on top of your toes in front that feels soft and where breathes ) under my faucet. Like, I suppose after 20 seconds of constant running water, it was still dry (very little dampness because I used hot water instead of cold or warm). So I am plenty satisfied with its waterproof claims. As for breathability, it has a little problem with that. It doesn't release enough in my opinion but its winter so Im fine with it. Hope this helps. Have a nice day peeps and don't stop exploring ^^